Parkinson's disease (PD) is a common disabling disease of old age affecting about one percent of the population over the age of 60 in the United States. The disease is associated with a reduction in dopamine release from the corpus striatum, leading to severe imbalance of dopamine/acetylcholine in the brain. Dopamine acts in the brain as a neurotransmitter in the synaptic cleft of the neurons, promoting signal transmission between cells.
Parkinson's is a progressively degenerative disease characterized by, among other symptoms, muscle rigidity, coarse tremors and postural deformity. Most conventional treatment methods try to ameliorate the resulting chemical imbalance by either reducing acetylcholine production and/or increasing dopamine concentration, with accompanying side effects that are the result of the new balance attained. One such method of treating PD involves the administration of a dopamine precursor like L-DOPA to promote dopamine release and the stimulation of its post-synaptic receptors. However, L-DOPA has a short half-life in the body and the effect of L-DOPA eventually becomes sporadic and unpredictable, resulting in fluctuations in motor function, dyskinesias and psychiatric side effects.
Thus, there is a need for a treatment of conditions characterized by decreased dopamine release. It is also desirable to have a treatment that will delay the onset of symptoms, and/or alleviate or retard symptomatic expression of the disease.